<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <div id="app"> hello
        <p>{{name}}</p>
        <span>{{age}}</span>
    </div>
    <script src="/dist/umd/vue.js"></script>
    <script>
        let vm = new Vue({
            el: '#app',
            data() {
                return {
                    arr: [1,2,3]
                }
            }
        })
        vm._data.arr.push(1);
        console.log(vm._data)
    </script>
</body>

</html>